Holding Onto A Thread
by Heteru911
Summary: Shizuo is left alone and confused after Izaya dies. What will he do now? And..what's with the secret lab under their house..? I suck at summaries XP There will be character death in the beginning, but it will get better, I promise! Rated for language and lemons.
1. Chapter 1: Broken Thread

**Holding Onto a Thread-**

**A Shizuo x Izaya Fanfic**

**Chapter 1: **

**Broken Thread**

The rain poured from the sky in hard, strong drops that day. The weatherman said the sun would shine that day. They never got it right. Of course, to him, it didn't matter. Not now.

_He's gone.._

_He won't come back.._

_We're sorry, Shizuo-san.._

_I wish there was something I could do.._

Their meaningless apologies floated through his mind every now and then when a large drop of water hit his head. What good did their words do? They couldn't bring him back. No one could bring him back.

_You're more than welcome to come.._

_We understand if you can't handle it, though.._

Shizuo Heiwajima looked down at the small group of black clothes and umbrellas from where he stood at a distance, leaning against an old tree on top of the cemetery's hill. The tree offered little shelter from the storm that raged both outside and inside of him as he looked solemnly at the little stone on the ground. Everyone insisted he come join the main group of mourners. He could see fine from where he was. He could see the stone with the name and dates of birth and death engraved on its rough surface. He could see the handful of people who'd actually bothered to show up for the funeral:

Two younger girls wearing matching black raincoats with fake animal ears. A woman around his age in a simple black business outfit standing under a black umbrella. Three kids-one girl with glasses and one young boy on either side of her-huddled together under a large umbrella. The tall black Russian man wearing only his uniform from the sushi restaurant, not bothering to protect himself from the rain at all. And a man he knew all too well dressed in a doctors coat and dragging a medical cooler behind him, both being kept dry by a black shield made of some strange energy projected by the woman next to him dressed in a black riding outfit and a black helmet instead of her usual yellow one.

It was kind of ironic and kind of sad. He always went on and on about how he loved humans. But, now that he was gone, these were the only humans who cared enough to say goodbye to him. Shizuo didn't count himself as one of them. He didn't come here to say goodbye. He came her because he couldn't. He couldn't say goodbye..

_How..?_

_How could it all turn out this way?_

_How could it have all been going so well..only to end like that..?_

He thought back to what seemed so long ago now. The last time he had seen him..

_Shizuo woke up to blinding sunlight pouring in through the window next to him. With a grumble, he rolled onto his side so he could attempt to ignore the day for just a while longer. It was his day off for God's sake. He should be allowed to sleep in a little! He closed his eyes and tried going back to sleep…_

_***clack* *clack* *clack***_

_ He shut his eyes harder, trying to ignore the sound.._

_***clack* *clack* *click* *click* *clack***_

_Okay..now that sound was getting obnoxious.._

_***clack* *clack* *click* *clack* *BREEP!* *clack***_

_He sighed. Damn it, it was way too early for this shit.._

"_DAMNIT, IZAYA-KUN! CANT YOU DO YOUR WORK SOMEWHERE ELSE?!" As Shizuo yelled these words he half-heartedly swung his fist at the source of the noise. His fist connected with sheets and pillows as his target moved just enough to avoid being hit. Shizuo raised his head up to glare at his missed target. It really was too early for this.._

"_Well, a good morning to you too, Shizu-chan." The cheerful-and way too awake for this time of day-voice of one Izaya Orihara replied._

_Shizuo glared at him as he sat up a little, making the sheets shift and fall off of him as he leaned against the pillows and headboard. Shizuo stretched out his naked body, kicking the sheets off the rest of the way. He looked at Izaya-who was also naked-sitting next to him on the bed with a sheet over his lap to protect his bare legs from his laptops cooling vents._

_Waking up like this had become pretty routine for him: Shizuo would wake up, naked, next to an equally naked Izaya who would almost always be wide awake and working on his laptop already. Shizuo would complain about being woken up by the sounds of the infernal computer. Izaya would retort that it wasn't that loud. Shizuo would try to punch him (actually succeeding sometimes, but sometimes getting cut with a knife instead). The two would lay around in bed for a while, Izaya working and Shizuo trying to accept the fact he was actually awake. Inevitably they'd get hungry and have a sort of stand-off to see who would break down and get up first to go cook breakfast. Shizuo preferred it when Izaya cooked because he usually made pancakes or waffles or something nice like that and he could lay around a while longer. Izaya always complained when Shizuo made breakfast because he was too lazy in the mornings and usually only made eggs (sometimes with bits of shell in them) or pulled out some cereal. During breakfast they would eat pretty quietly, occasionally informing each other about any plans for the day and the occasional question of what to do for dinner that night. After they finished eating Izaya would do the dishes (he preferred his house to stay clean) while Shizuo took a quick shower and got dressed. By the time Shizuo was done in the shower Izaya would already be dressed and flopped face down on the bed with his feet kicking in the air. Shizuo would sit on the bed and put his socks and sunglasses on, talking with Izaya for a while before it was time to go to work. Sometimes, for fun, he'd sit on Izaya when he wasn't paying attention, or pinch his ass, or grab him in a leg-lock; really, anything just to mess with the informant and piss him off a little. After they were done talking (or trying to kill each other, depending on the day) Shizuo would go meet Tom for work and Izaya would stay at home, saying he had some work to do in his office before heading out._

_This routine had become fairly comfortable to Shizuo over time. Although, to be honest, it didn't mean his relationship with Izaya was exactly "normal" or "stable" or any of those pleasant, safe words people use to describe a relationship where two people have been together for practically two years and currently live together. They were far from being sweet and romantic like Shinra and Celty. They would often joke that if they ever acted like those two they'd go ahead and kill each other- they would rather die than be so sweet and friendly. Their relationship was about as far from sweet or normal as you could get. When one of them got mad windows or walls would break and furniture would be thrown. When they had sex they'd both walk away with bite marks, cuts, bruises, and sore limbs. When they-on the rare occasions-went on dates there would be trails of unconscious people and broken streets. This relationship wasn't safe, normal, sweet, friendly, romantic, or anything that seemed nice like that. People trembled in fear at the image of the two breaking up, often saying Ikebukuro would be wiped off the map during the inevitable fight._

_Despite all the negativity, doubt, violence, and destruction people associated with Shizuo and Izayas relationship it somehow worked for them. They'd never admit they were happy together (not even to each other) and would only ever say that, for some reason, they were..comfortable. That was all they could really think to say. What more was there TO say? They were content and comfortable with their relationship. They liked waking up together. They liked eating together. They liked arguing about what to eat, where to go for a date, what to watch on TV, etc. They DEFINITELY liked the rough, no-holding-back sex. They even liked it when they fought (even though Shizuo so often denied it due to his hatred for violence). Truth be told, they both enjoyed their relationship the way it was. It wasn't a relationship normal humans would have, but they weren't normal humans. Izaya would even go as far as to say their relationship worked because they weren't human: they were monsters. Whatever the reason, Shizuo was happy with this relationship and routine he'd gotten used to._

_He briefly thought about all of these things as he put his socks on and reached for his sunglasses. Izaya was lying underneath him (Shizuo felt like sitting on him today), occasionally squirming or struggling before he eventually stopped with a sigh of defeat (for now). "Ne, Shizu-chan.."_

_Shizuo put his sunglasses on, glancing down at Izaya using his peripheral vision. "What is it, Flea?"_

_Izaya laid his head to the side so he was looking at the headboard. "What do you like about me?"_

_Shizuo leaned his head back lazily. "Who said I actually like you?"_

_Izaya chuckled and wiggled his feet. "True, true..I don't suppose you'd admit you loved me either, huh?"_

_Shizuo coughed into his hand, hoping to pass it off as a sarcastic gagging noise and hide the slight tint on his cheeks. "Are you high or something?" Seriously, what was up with Izaya? Asking these sort of questions so early in the day.._

_Izaya tilted his head enough so Shizuo could see him smirking. "No, I haven't gotten into your stash yet. And you didn't answer me."_

_Shizuo looked away, mumbling as he spoke. "Shut up, Flea..like I'd ever admit to something like that.."_

_Izaya smirked more, eyes gleaming like he knew something. "Ne, Shizu-chan..you're a bad liar..3"_

_Shizuo punched Izaya in the arm without looking at him, making the trapped informant wince a little but his smirk didn't falter. "I said shut up damn it.." These questions were making him uncomfortable. He had never been good with words. He preferred actions to words any day. Besides, he wasn't ready to admit he loved Izaya just yet..that could wait until his little surprise was ready.._

"_Shizu-chan.." Shizuo glanced back down at Izaya to see he had adjusted his head- his chin now resting on the bed so his head was straight up and he was looking at the wall in front of him. His tone of voice had changed as well. He sounded almost serious. Almost. "…What would you do if..I died..?"_

_Shizuo blinked behind his sunglasses but didn't let the slight surprise and curiosity show on his face. "Depends. Did I kill you?"_

"_No, it was some sort of accident neither of us had any control over.." His voice sounded odd when he was like this._

"_Hm.." Shizuo looked up at the ceiling in thought. What WOULD he do? "If you died..I'd probably stay away from your funeral, throw a cigarette on your grave..then go down to hell and kill you again for dying like that.."_

_Izayas body trembled slightly under Shizuo before he threw his head back in an almost hysterical fit of laughter. This made Shizuo jump slightly and stare down at the (more than likely psychotic) man under him. After a minute or so of laughter Izaya calmed down and wiped the tears from his eyes. "Ah, Shizu-chan..I knew you were going to say something like that 3"_

_Shizuo sighed in annoyance and smacked the back of Izayas head. "Why were you asking anyway? You planning to die or something?"_

_Izaya shook his head and looked back at Shizuo with a grin. "No, Shizu-chan would miss me too much 3" Izaya dodged another blow to the head and smiled more. "I was just curious. Especially since I won't be in town today."_

_Shizuo tilted his head slightly. "Oh yeah? Where are you going?"_

_He decided it was about time to go to work so Shizuo stood up while he listened. Izaya gladly took this opportunity to roll onto his back and sit up, looking at Shizuo more clearly now. "I have to go to Hokkaido today for something I can't tell you about." That last part was an answer Shizuo had become accustomed to regarding Izayas job. "Namie booked me a round-trip ticket and it's not too far away. The plane should be back here before dinner tonight."_

_Shizuo nodded to show he was listening as he readied a cigarette for when he got outside- Izaya always cut his cigarettes in half if he smoked in the house because he hated the mess they made. "Oh..So, you're asking because you're scared of flying or something?" He knew that wasn't true, but he wanted to mess with him one more time before he left._

_Izaya chuckled a bit and shook his head. "No, I've been on planes several times..but, they do have a bad reputation for crashing." He stood up and stretched, his movements a bit exaggerated. "Well, I'll see you tonight, Shizu-chan." He smirked as he gave Shizuo a quick hug and a peck on the lips before running out of the bedroom to his office._

_Shizuo was left to blink in confusion before he saw the clock and realized what time it was. He left the house and walked quickly to meet Tom. He'd ask Izaya about his odd behavior later.._

It was horribly cliché and almost sappy to admit but..later never came. The plane Izaya was on crashed on its way back to Ikebukuro. It wasn't even an hour away. It wasn't fair…

"Shizuo? Shizuooo?"

He blinked, snapping back to reality. He looked down at the cigarette that had been between his lips-now nothing but a butt and a lot of ash-and spit it on the ground before stomping on it with his foot. When he looked back up he noticed Shinra and Celty standing in front of him, the look on Shinras face told him he'd been calling Shizuos name for a while now. He peered above their heads and noticed everyone else was already gone. He shook his head and sighed. "Sorry..were you saying something?"

Shinra nodded, looking slightly concerned. "Yeah. I was asking if you were okay. You've been standing here for a while. Everyone else already left."

Celty pulled out her cellphone and quickly typed a message on it before showing the screen to Shizuo. "You were really spaced out. Shinra called your name at least 5 times." She turned the phone back around and typed again before showing the screen to Shizuo once more. "Are you going to be okay? It's never easy when you lose someone you care about…"

Shizuo took a minute to just look at the screen before casually pulling out a new cigarette, cupping his hands around the end so he could light it. "I don't know why you're asking me.." He brought the cigarette to his lips and inhaled, blowing out a slow stream of smoke before looking up at the sky. "I didn't like that damn flea…"

Shinra frowned slightly and folded his arms. "You know, you don't have to say that around us. We all knew you two were together."

Shizuo shot him a look that made Shinra jump slightly and hide behind Celty nervously. "So?"

Celty quickly typed on her phone and showed the screen to Shizuo again. "So, if you ever need to talk about I-" She quickly turned the phone back around and altered the text before showing Shizuo again. "about anything, I'll be available." Shizuo nodded and only glanced back once Celty finished typing another message. "Take care of yourself, Shizuo. I'll see you around." She bowed a little and led Shinra away.

Shinra waved to Shizuo as he followed Celty. "See you, Shizuo!"

Shizuo nodded and took another drag from his cigarette as he watched them leave. His eyes landed on the large, four-wheeled medical cooler dragging in the mud behind Shinra. He had to stop himself from shuddering. Apparently Izaya and Shinra had some sort of arrangement that Shinra could take Izayas heart, lungs, liver, brain, etc., for medical study if Izaya died before him. That fact wasn't what bothered Shizuo. What bothered him was that Shinra had harvested the organs before Izaya was buried. That, and the fact that Shinra was walking around the funeral, dragging the cooler with him like it was perfectly natural to bring the dead person's organs to their own funeral. It was sickening to think that parts of Izaya were still in that cooler...

He watched as Shinra loaded the cooler into his car. Celty waited patiently beside him on her black motorcycle. They had decided to come in separate vehicles so Shinra could bring his tools and cooler easier. Shizuo watched them drive off together once Shinra had everything secured.

Now he was completely alone.

He made his way down to the small tombstone, the mud trying to swallow his shoes. He stopped about a foot away from the tombstone and looked down at it and, for a minute, he felt..nothing. He didn't feel sad that the person he lived with was gone. He didn't feel happy that the man who he wanted to kill for so many years was finally dead. He didn't feel rage that Izaya died and he wasn't the cause. He simply felt nothing.

Shizuo finished his cigarette and sighed. He may as well follow through with what he said. He carelessly flicked what was left of his cigarette onto the grave, stomped on it, and walked away.

"Now to figure out a way into hell…"


	2. Chapter 2: Frayed Thread

**Chapter 2:**

**Frayed Thread**

Shizuo dropped the pile of empty boxes onto the bedroom floor and watched them spread out and spill across the hard, wooden surface. With a sigh he sat on the large bed in the middle of the room and looked up at the ceiling. He hadn't slept in this room since Izaya died. He couldn't stand the thought of sleeping alone in this bed. Sleeping with Izaya every night had become part of his routine…now, that routine was gone.

After a minute of depressing thoughts and musing on his ruined daily routine Shizuo decided to get up and start packing the empty boxes. Moving out of this house seemed like the best thing for him for many reasons: First of all it felt way too big with only one person staying here (it was perfect for two people, but he just felt small without someone else there). Secondly he didn't want to stay in a house where he couldn't sleep in his own bedroom (he had been sleeping on the couch and his back was really starting to ache from it). The third reason was because he didn't know whether or not he could even AFFORD to live here anymore- the house was in Izayas name and he had paid all of the bills (Shizuo would help out by paying for the groceries, anything they had to buy, covering repair bills, and picking up the check when they went out to eat). The fourth and final reason was something he didn't even want to admit to himself-

Being in this house made him depressed because…he actually missed that damned black haired, red eyed, pain-in-the-ass flea of a man.

Shizuo lost track of how long he spent packing the boxes, but he knew he must have been at it for at least three hours. He briefly contemplated on taking a break but decided he may as well finish and be done with it for good. He sat down in front of the nightstand next to his side of the bed and opened the drawer. Briefly debating about keeping certain items before throwing them into the open box behind him didn't take very long at all. The last thing in the bottom of the drawer was some ratty old notebook he wasn't even sure was his. Out of curiosity he opened the notebook and flicked through the pages, letting his eyes briefly scan over the handwriting. It appeared to be Izaya's distinctively neat penmanship and must have been in there before Shizuo started spending nights at that house.

His eyes glanced up to a dent in the wall above the nightstand. That little incident happened the first time he found out about this house. Apparently Izaya bought this house a few years ago. He said going back and forth between Ikebukuro and Shinjuku was easy enough, but sometimes he didn't feel like spending the few hours of travel it took to get back to his apartment after a long day of ruining lives and getting people to kill themselves. Izaya also used this place as a back-up office when people started looking for him too much in Shinjuku or when he wanted to stay in Ikebukuro for long periods of time…usually to mess with Shizuo. Soon after Izaya and Shizuo had started their odd relationship they realized it was a bit troublesome going between the two towns every time they wanted to see each other. The look in Izaya's eyes told Shizuo that Izaya wasn't telling him something and he called him on it. Needless to say, when Izaya showed Shizuo the house a fight erupted between the two. It pissed Shizuo off that he had told the flea (multiple times) to stay the hell out of Ikebukuro and said flea just turned around and bought a HOUSE! It was the first of many fights in that house that resulted in thrown furniture and broken walls. The escalating trail of violence ended up in the bedroom with Izaya standing near the nightstand and Shizuo glaring down at the trapped informant. He threw a hard punch aimed right at Izayas face, but the bastard was quicker and managed to jump onto the bed. After Shizuos fist connected with the wall he had every intention of smashing the annoying man's face straight through the dent, but was pulled down onto the bed and given a different outlet for his aggression-based adrenaline and uncontrollable strength. That day was their first fight in the house, the first time walls were broken in the house, and the first time they made love all through the night in the house. That day had been the first of many things that soon became the norm for them.

Shizuo had spaced out for a bit while remembering that day and didn't realize he was still flicking aimlessly through the pages of the notebook until he ran out of pages and his thumb hit the cardboard back of the notebook. He looked down at it and was about to put it back in the drawer but stopped when he noticed something interesting: There was a small key taped to the cardboard. From the condition of the tape it looked like it had been there for a while and was constantly removed and reattached. Did Izaya move Shizuos stuff constantly to get to this thing? Shizuo carefully pulled the tape off the key and picked it up, looking it over out of curiosity. It definitely wasn't the key to the front or back door-he had his own copy and knew it was way too small to fit in those locks- and none of the doors he knew of in this house had key holes in them. The only thing he could think of was that it must have been to something in Izayas office.

He carefully turned the key in his fingers for a minute of contemplation. He really should find what the key went to...But what if it was something private? Izaya didn't really need privacy anymore considering he was dead…But what if it was a waste of time and the key didn't go to anything in the house? He could just throw it away if he didn't find anything, or give it to that secretary…But what if-

"Leave it to that damn flea to piss me off and confuse the hell out of me from beyond the fucking grave!" Shizuo sighed irritably and stood up. His eyes looked over the sea of boxes around the room. They were all full and sealed, ready to be moved whenever he was ready. He looked back to the key in his hand and scratched his head with his free hand. "I'll just see if this goes with anything in his office…if it doesn't, then I'm out of here."

With his decision made, Shizuo carefully climbed over the bed to avoid the boxes and walked down the hall to Izayas office. Looking over the door made him realize that he had only been in there a few times…usually just to ask Izaya a quick question. He opened the door and slowly looked around the office, actually taking in the details for the first time:

It was a pretty standard office room. There were two large, very full bookshelves set up against the far wall. A mahogany desk stood proudly in the middle of the room, but its image was marred by the unorganized stacks of paper across its surface, the pens and pencils precariously perched on top of the mountainous paperwork, and the half-turned away black swivel chair that should have been properly pushed into the desk instead of sitting a few feet away like someone had just jumped out of it and left it there (which, knowing Izaya, was very likely). Izayas laptop was laying on a corner of the desk and would probably fall off if it was bumped a certain way. When all was said and done, though, this office was pretty normal compared to the person who used it so frequently.

After taking in his surroundings Shizuo began looking for anything the little key could go to. Since he didn't see any keyholes immediately visible, it was probably something hidden like a safe or a secret compartment on the desk. Shizuo carefully moved the laptop so it wouldn't fall before he sat in the swivel chair and looked over the impressive yet messy mahogany desk. There were only five drawers that he could see- two on each side of his legs and a long, skinny one above his lap. He decided to work his way up and started with the bottom drawers. All he found in those were more papers, files, and quite a few knives he was well acquainted with… The top two drawers were about the same and had pictures and profiles of several people he really didn't care for. That just left the middle drawer over his lap. He rolled the chair back slightly so he could open the drawer all the way and look inside. It just looked like a drawer for pens, pencils, sticky notes, paper clips, and other office supplies. With a sigh of defeat and exasperation, Shizuo leaned back in the chair. It looked like this key was just a waste of time…

He leaned his head up, preparing to leave the office and house altogether, but thought he saw something glinting in the back of the drawer. It was probably just a paper clip or a pen or something…but, he decided it couldn't hurt to check. Shizuo carefully slid his hand all the way to the back of the drawer and felt around for a minute. His fingers brushed against something round and metallic against the back wall of the drawer near the top. After trying to pull it off and poking at it repeatedly he realized that whatever it was wasn't coming off and was more than likely built into the drawer. It felt like it had some sort of jagged hole. Maybe the key would fit here? Shizuo grabbed the key and slid his hand back into the drawer. After fumbling for a minute or two with getting the key into the hole it finally slid in properly and turned with an audible "click" followed by a soft "thump" off to Shizuos right. He looked up and noticed one of the books from the bookshelves had fallen onto the ground.

"How the hell..?" Shizuo said with a confused blink of his eyes. He got up and walked to the book, picking it up before he looked up at the hole in the otherwise packed row of books. There was some sort of hidden panel along the back of the shelf where the book had been. It looked like it was held with some sort of spring-lock mechanism, most likely activated by turning the key in the desk.

With his curiosity beyond peaked now, Shizuo lifted the hidden panel up until he saw a little red button embedded in the wall behind the bookshelf. He briefly pondered on why buttons were often red as he pushed it with just enough force to activate it. The bookshelf swung open without any warning, barely giving Shizuo enough time to avoid being hit by the enormous wall of books.

"Whoa! The fuck-?!" Once he was fairly certain the shelf wouldn't move again, Shizuo cautiously moved closer and peeked inside…and what he saw made his jaw drop. "H..How..what..?" Shizuo wasn't good with words on a normal day, and this day was going so far past normal it was entering another county. What he saw on the patch of wall, previously hidden by the large bookshelf, was a winding, spiral staircase leading down below the house. Seriously, how long had THAT been there?! He took a step into the small area and looked down. The stairs went down further then he could see- which meant quite a lot considering the staircase was well lit and his eyesight wasn't THAT bad.

Shizuo heard the bookcase click and saw it start to move back into place. Something in his mind told him he had to make a decision: Should he see how far this weird little mystery goes…or just forget he ever saw anything and leave it for someone else to mess with? Shizuo was never good with mental debates, and just went with his gut.

Taking in a breath, he let his body guide him and stepped down the stairs quickly, barely avoiding the bookcase once again as it closed. He stole a quick glance back at the door but kept walking, trying to avoid the temptation of changing his mind. It took him at least a good five minutes to walk down the spiral staircase (seriously, how fucking deep was this thing?!). When he finally got to the bottom, Shizuo had to stop for a minute and hold his head. He officially hated spiral staircases now. _

After everything felt level again, Shizuo glanced up for a second…then did a double-take and stared with large, bewildered eyes. Okay…normal was officially in another country now. He fumbled around on the wall and found a light switch, flicking it on to make sure what he was seeing was real and not just a dizzy-spell induced illusion.

As the lights flicked on, he got his answer: this shit was real.

The lights along the ceiling allowed him to see a large, spacious laboratory. Along one wall were some human-sized, liquid filled tubes like something out of a sci-fi movie. There was also a large refrigeration unit built into another wall, along with a wardrobe that had one door open enough to reveal a collection of lab coats, and a small work table with a chair. Finally-and this is what made Shizuo's jaw drop-there was a huge (bigger than any he had ever seen before), more than state of the art, SUPER COMPUTER that took up a **whole **wall by itself!

Shizuo stared in a mixture of shock, amazement, and wonder. How the hell had the flea managed to hide all of this for so long?! Of course, given who he was talking about, it really shouldn't be that hard to believe…

Apparently flicking on the lights also sent power to the computer. Shizuo came to this conclusion when the previously powerless computer began to light up. The screen flickered to life, instantly bringing up some program in another language that Shizuo couldn't read.

"What the..?"

"Huh..that sounds like someone different.."

Shizuo blinked, his eyes widening at that voice. It..It couldn't be…could it..? He looked at the computer.

"I..Izaya..?"


End file.
